Charge flow in metals and mass flow in a neutral Fermi liquid show dis
tinct profiles and are governed by different conservation properties.
The connections between these two aspects of flow become apparent when
we study the viscous flow of normal liquid He-3 in the presence of ae
rogel. While the thermal flow is trivially affected, we predict that t
he resistance to mass flow shows a crossover from Drude's to Hagen-Poi
seuille's law with varying temperature and low aerogel concentration.
This crossover should be observable in de-flow experiments. [S0031-900
7(98)07528-0].